Objective: To estimate the health-related quality of life (HRQoL) in a group of obese children and adolescents from the city of Hermosillo, Sonora, Mexico. Methods: A cross sectional study was performed using the PedsQL® questionnaire to compare the HRQoL of 200 children and adolescents with obesity as well as their parents, with two control groups: one from the community (n=400) and another group of users (n=200) from the Hospital Infantil del Estado de Sonora. The differences in HRQoL were assessed using a Kruskal-Wallis test and their relationship with sociodemographic variables and physical status was examined with logistic regression. Results: HRQoL was lower in obese patients. Social and emotional QoL were lower in obese subjects. Perception of parents on HRQoL was lower than that of their children. 37.5% of obese subjects perceived their HRQoL as "very bad", which was lower than control groups. The risk of poor HRQoL was 2.2 times higher in the obese group. Conclusions: Obesity impairs HRQoL in children and adolescents. PedsQL® is a useful tool for the systematic assessment of HRQoL in children with obesity.